The use of self-service vending machines to dispense food, beverage(s), movies and other items is well-known in the art. A majority of these vending machines are generally located outside a storefront to save retail space within the interior of the store. Locations where containers for LPG (liquid petroleum gas, or propane) will be stored and potentially vended require special vending systems that can adhere to appropriate rules for Class I Division 2 hazardous locations. As recognized by those familiar with the regulations involved, Class I locations are those in which flammable vapors and gases may be present. In more detail, Division 2 locations are generally described as those locations where flammable vapors and gases are present only in abnormal circumstances, such as those areas where ignitable concentrations of hazards are handled, processed or used, but which are normally in closed containers or closed systems from which they can only escape through accidental rupture or breakdown of such containers or systems. In most cases where propane tanks are stored, sold or exchanged, the tanks are housed in locked metal cages. To purchase, the customer has to go inside the store to make a payment for these items, a store employee must locate the key, go outside, unlock the cage and remove one of the tanks. Obviously, this is somewhat inconvenient, time consuming, inefficient and in many cases cannot be accomplished at all due to a lack of store personnel available to complete the task. To have automated systems in the above mentioned Class I Division 2 locations, several requirements must be met. Generally, any electrical system must operate at low voltage, low amperage, and cannot have any make/break electrical connections which are not sealed (or intrinsically protected or safe using other mechanisms). Thus, systems capable of vending products in these locations must be carefully designed.
If the large items are stored in locked containers outside the store to deter theft, the customer may have to wait a period of time for the store personnel to come out and unlock the containers to access the items. This inconvenience of waiting for assistance from store personal to access these bulky items and pay for them can be frustrating. This frustration is further magnified if the store is closed for the day and the customer has to make another trip to the store when it is open to purchase the items. Additionally, having the products locked up and inaccessible to customers when the store is closed precludes the efficient sale and profitability of these items during extended/non-traditional business hours.
Vending machines for dispensing propane tanks and other items requiring Hazardous Location considerations have existed and are somewhat known. For example, U.S. Pat. No. 6,761,194 (Blong) describes a system for dispensing a plurality of pressurized propane tanks. However, none of the existing vending systems for dispensing items uses a modular approach that has the capability to quickly add-on and efficiently integrate additional modules to the main systems, such as by connecting a wiring harness from the existing module's computing hardware to the new module's computing hardware or to attach wiring directly to the existing module without adding additional computing hardware and attaching the new module. Stated differently, none of the existing systems use module attachment hardware to accommodate expansion. Prior art hazardous location vending systems generally utilize an inert gas system, or are mechanical in nature, to open doors or make the product available to customers. These systems are susceptible to failure, due to the number of components involved and the exposure to harsh environments (i.e. rain, dirt/debris, etc.).
As further examples, U.S. Pat. No. 8,712,585 (Bruck et al.) describes a vending apparatus and system that includes the use of optional modules and U.S. Pat. Appl. Pub. No. 2015/0102051 (Shimmerlik et al.) describes a modular vending machine system with re-loadable vertical product dispensing modules. These prior art vending systems are meant for use within a store to dispense consumable products and not for dispensing large and bulky items requiring a hazardous location designation such as propane tanks.
Therefore, there is a need for a modular outdoor vending system capable of storing and dispensing propane tanks (of various sizes) and other items that must be stored in and dispensed from a hazardous location compliant system. There is a further need for a vending system that does not require continuous AC power for its operation. The vending system can ideally be operated using DC batteries which can be continuously charged by AC power or a solar power so that the system continues to operate during power interruptions.